Young’s Modulus of Elasticity in the MKS system is measured in N/m^2. This unit represents the ratio of stress to strain and is a measure of a material's stiffness.

Explanation:
1. Young's Modulus: Young's Modulus, also known as the modulus of elasticity, is a material property that describes how much a material will deform under a given amount of stress.
2. Unit in MKS System: In the MKS (meter-kilogram-second) system, Young's Modulus is expressed in Newton per square meter (N/m^2) or Pascal (Pa).
3. Relation to Stress and Strain: Young's Modulus is calculated as the ratio of stress (force per unit area) to strain (unitless measure of deformation). The formula is given by E = stress/strain.
4. Physical Interpretation: A material with a high Young's Modulus will deform less under a given amount of stress compared to a material with a lower Young's Modulus. It is an important parameter in material selection for engineering applications.
5. Example: For example, steel has a high Young's Modulus, indicating that it is a stiff material that requires a large force to deform it. In contrast, rubber has a low Young's Modulus, making it more flexible and easier to deform.
In conclusion, Young's Modulus in the MKS system is measured in N/m^2, representing the stiffness of a material and its resistance to deformation under stress.